The invention relates generally to a set of iron-type golf clubs. In particular, the invention relates to a set of irons with substantially constant ground roll.
In a set of irons, various design characteristics are varied from one club to the next. For example, individual iron club heads in a set typically increase progressively in face surface area and weight as the clubs progress from the long irons to the short irons and wedges. The shaft length shortens as the clubs progress from the long irons to the wedges, and the loft angle typically increases through the same progression. These design variables and others can be modified so that a particular club, for example a 3-iron, produces certain flight characteristics. Specifically, the clubs are designed to produce specific launch angles and to impart a certain amount of backspin to the ball, when the ball is struck correctly, i.e., with an anticipated speed and at the nominal hitting point, typically a point on the hitting face about 18 mm or less above the ground when the club is in the address position. When struck in the appropriate manner, the combination of ball speed, launch angle and backspin produces an anticipated flight path, with the ball achieving a specific height at the maximum point of the parabolic arc of the path and a specific carry distance.
In traditional iron sets, flight path height (distance above ground) and carry distance are generally the performance parameters which a golf club is designed to achieve. However, another parameter, ground roll of the ball, is relatively neglected in the overall design of the club, with ground roll being dependent upon the design characteristics selected to achieve a specific flight path. As such, traditional iron sets result in longer shots having the ball roll more on a green than do the shorter shots. This creates difficulty in hitting long shots which will stop on a green. Also, some short shots can roll backwards on the green. As a result, precisely controlling the total distance achieved by a shot may prove difficult if the player cannot accurately account for ground roll distance. A shot hit with a club from an iron set would be easier to control, i.e., the distance attained for a shot from each iron would be more predictable, if each would roll a prescribed distance.
Therefore, a need exists for a set of iron clubs having predictable ground roll. Such a set of clubs may have the same ground roll for each club in the set.